Department of Psychology, Clinical Neuroscience, Self-regulation and Biological Psychology Laboratory, University of Tennessee, Knoxville, TN 37996, USA.
Clin EEG Neurosci. 2012 Oct;43(4):257-67. doi: 10.1177/1550059412449780.
In recent years, there has been an increasing line of research dedicated to the investigation of the default mode network (DMN) of the brain and resting state networks. However, the mental activity of the DMN has not been rigorously assessed to date. The specific aims of the current study were 2-fold: First, we sought to determine whether the current source density (CSD) levels in the DMN would correspond to other neuroimaging techniques. Second, we sought to understand the subjective mental activity of the DMN during baseline recordings. This study was conducted with 63 nonclinical participants, 34 female and 29 males with a mean age of 19.2 years (standard deviation = 2.0). The participants were recorded in 8 conditions. First, 4-minute eyes-closed baseline (ECB) and eyes-opened baseline (EOB) were obtained. The participants then completed 3 assessment instruments and 3 image conditions while the electroencephalography (EEG) was continuously recorded. Participants completed subjective reports for baselines and image conditions. These were rated by 3 independent raters and compared for reliability using a random effects model with an absolute agreement definition. The mean CSD between all conditions differed significantly, in many but not all regions of interest in the DMN. Interestingly, as suggested by other studies, the DMN appears preferential to self-relevant, self-specific, or self-perceptive processes. The reliability analyses show α for interrater agreement for ECB at .95 and EOB at .96. The subjective reports obtained from the participants regarding the mental activities employed during baseline recordings correspond to attentional and self-regulatory processes, which may also implicate the resting state or DMN as playing a direct role in the maintenance of a complex behavior (eg, being still, attending, and self-regulating). Thus, attention and self-regulation constitute the phenomenology of the resting state (DMN) in this study. The results also demonstrate that EEG CSD is a useful method to examine the DMN during concept-specific tasks to elucidate the neural activity associated with these concepts. Standardized low-resolution electromagnetic tomography (sLORETA) can localize to 5 mm(3), which is comparable to the findings in functional magnetic resonance imaging (fMRI). However, sLORETA can provide data about the difference in activity between groups, individuals, or populations which in many cases fMRI cannot provide.
近年来，越来越多的研究致力于研究大脑的默认模式网络 (DMN) 和静息态网络。然而，迄今为止，DMN 的心理活动还没有得到严格的评估。本研究的具体目的有两个：首先，我们试图确定 DMN 的当前源密度 (CSD) 水平是否与其他神经影像学技术相对应。其次，我们试图了解基线记录期间 DMN 的主观心理活动。本研究共纳入 63 名非临床参与者，其中 34 名女性，29 名男性，平均年龄 19.2 岁（标准差=2.0）。参与者在 8 种情况下被记录。首先，获得 4 分钟闭眼基线 (ECB) 和睁眼基线 (EOB)。然后，参与者在连续记录脑电图 (EEG) 的同时完成 3 项评估工具和 3 项图像条件。参与者完成了基线和图像条件的主观报告。这些报告由 3 位独立的评分者进行评分，并使用具有绝对一致性定义的随机效应模型进行可靠性比较。所有条件之间的平均 CSD 差异显著，在 DMN 的许多（但不是所有）感兴趣区域中都有差异。有趣的是，正如其他研究表明的那样，DMN 似乎偏向于与自我相关、自我特定或自我感知的过程。可靠性分析显示，ECB 的组内信度为.95，EOB 的组内信度为.96。参与者在基线记录期间进行的心理活动的主观报告与注意力和自我调节过程相对应，这也可能意味着静息状态或 DMN 在维持复杂行为（例如，保持静止、注意和自我调节）中发挥直接作用。因此，在本研究中，注意力和自我调节构成了静息状态（DMN）的现象学。结果还表明，脑电图 CSD 是一种在概念特定任务期间检查 DMN 的有用方法，以阐明与这些概念相关的神经活动。标准化低分辨率电磁层析成像 (sLORETA) 可以定位到 5 毫米立方，与功能磁共振成像 (fMRI) 的发现相当。然而，sLORETA 可以提供关于组间、个体或人群之间活动差异的数据，而在许多情况下，fMRI 无法提供这些数据。
